Research suggests that cardiovascular reactivity to psychological stress may contribute to the development of cardiovascular disease. Most of this research has focused on the magnitude of cardiovascular responses to acute stress, rather than on patterns of cardiovascular responses to recurrent stress. An analysis of patterns of cardiovascular reactivity to recurrent psychological stress may aid in understanding cardiovascular disease processes. Three studies are proposed to examine such patterns using rival predictions derived from competing theories of cognitive appraisal and habituation. All three studies will examine the psychophysiological effects of different amounts of exposure to a stressful mental arithmetic task, and the impact of prior cardiovascular adaptation to that task on subsequent cardiovascular reactivity to a change in stimulation. In Study 1, the change in stimulation will involve evaluative videotaping during a familiar task, whereas in Study 2 the change will involve monetary incentives for successful performance of a familiar task. Study 3 wifl examine the effects of repeated exposure to one type of stressor on subsequent cardiovascular reactivity to a different type of stressor. Gender and individual differences in cardiovascular reactivity and adaptation to recurrent stress will also be evaluated. Noninvasive procedures will be used in all studies to record cardiovascular, electrodermal, behavioral, and subjective responses of men and women during psychological stress. Cardiac and vascular response patterns are expected to diverge with repeated exposure to stress, with cardiac performance showing decrements and vascular resistance showing increments. It is predicted that a change in stimulation will disrupt cardiac adaptation and potentiate the rise in vascular resistance, thereby enhancing cardiovascular reactivity. Gender and certain individual differences are expected to moderate patterns of cardiovascular reactivity to recurrent stress. This research has implications for (a) the relationship between stress and cardiovascular disease, (b) the design of psychophysiological stress tests, (C) the development of stress tolerance, and (d) the connection between acute and chronic stress.